(PowerShell) JWE using ECDH-ES, BP-256, A256GCM

See more JSON Web Encryption (JWE) Examples

Create a JWE with the following header:

	{
	  "alg": "ECDH-ES",
	  "enc": "A256GCM",
	  "exp": 1621957030,
	  "cty": "NJWT",
	  "epk": {
	    "kty": "EC",
	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
	    "crv": "BP-256"
	  }
	}

Note: This example requires Chilkat v9.5.0.87 or greater.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# Load our brainpool BP-256 public key.

# 	{
# 	  "use": "enc",
# 	  "kid": "puk_idp_enc",
# 	  "kty": "EC",
# 	  "crv": "BP-256",
# 	  "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w",
# 	  "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
# 	}

$json = New-Object Chilkat.JsonObject
$json.UpdateString("use","enc")
$json.UpdateString("kid","puk_idp_enc")
$json.UpdateString("kty","EC")
$json.UpdateString("crv","BP-256")
$json.UpdateString("x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w")
$json.UpdateString("y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu")

$pubkey = New-Object Chilkat.PublicKey

$success = $pubkey.LoadFromString($json.Emit())
if ($success -eq $false) {
    $($pubkey.LastErrorText)
    exit
}

# Build our protected header:

# 	{
# 	  "alg": "ECDH-ES",
# 	  "enc": "A256GCM",
# 	  "exp": 1621957030,
# 	  "cty": "NJWT",
# 	  "epk": {
# 	    "kty": "EC",
# 	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
# 	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
# 	    "crv": "BP-256"
# 	  }
# 	}

# Use jwt only for getting the current date/time + 3600 seconds.
$jwt = New-Object Chilkat.Jwt

$jweProtHdr = New-Object Chilkat.JsonObject
$jweProtHdr.UpdateString("alg","ECDH-ES")
$jweProtHdr.UpdateString("enc","A256GCM")
$jweProtHdr.UpdateInt("exp",$jwt.GenNumericDate(3600))
$jweProtHdr.UpdateString("cty","NJWT")
$jweProtHdr.UpdateString("epk.kty","EC")
$jweProtHdr.UpdateString("epk.x","QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w")
$jweProtHdr.UpdateString("epk.y","AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu")
$jweProtHdr.UpdateString("epk.crv","BP-256")

$jwe = New-Object Chilkat.Jwe
$jwe.SetProtectedHeader($jweProtHdr)
$jwe.SetPublicKey(0,$pubkey)

$plainText = "This is the text to be encrypted."
$strJwe = $jwe.Encrypt($plainText,"utf-8")
if ($jwe.LastMethodSuccess -ne $true) {
    $($jwe.LastErrorText)
    exit
}

$($strJwe)

$("Success.")